|
USA | |
|
| Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87. |
|
| Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193. |
- Oro Blanco Mining District (Ruby Mining District)
| Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193. |
|
| Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Lewis, W. Scott (1942), Gem collecting in California: Hobbies: 47: 116-117 |
- Bradshaw Mountains (Bradshaw Range)
- Castle Creek Mining District
| Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87. |
- Wilson Springs (Potash Sulfur Springs)
| Owens, Don R. (1995) Minerals of the Wilson Springs Vanadium Mines, Potash Sulphur Springs, Arkansas. Rocks & Minerals: 70(3): 154-170.
Howard, J. Michael |
- El Paso Mountains District
| Christopher N. Wentzell |
|
| Christopher Wentzell |
- Knoxville Mining District
| |
|
| Extra Lapis - English No. 10 Opal |
|
| Extra Lapis - English No. 10 Opal |
|
| The Moscow Opal Mines 1890 to 1893 (The First Commercial Opal Mines in the United States), Ron Brockett, 1975 |
|
| Dake, H. C. (1956) Northwest Gem Trails - A Field Guide for the Gem Hunter, Mineral Collector and Tourist (2nd ed.) Gembooks. |
|
| Christopher Wentzell collection (2020) and personally verified on site (2020) |
|
| Extra Lapis - English No. 10 Opal |
|
| Dake, H. C. (1956) Northwest Gem Trails - A Field Guide for the Gem Hunter, Mineral Collector and Tourist (2nd ed.) Gembooks. |
|
| R&M 69:3 pp 156-162 |
|
| The Minerals and Gemstones of Nebraska CSD U Neb EC 2 |
|
| The Minerals and Gemstones of Nebraska CSD U Neb EC 2 |
|
| The Minerals and Gemstones of Nebraska CSD U Neb EC 2 |
|
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology |
|
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology |
|
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology |
|
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology |
|
| [var. Black Opal] Betts, John (n.d.) John Betts website listing. |
|
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology
USGS Bull 1538D |
|
| Christopher Wentzell |
|
| Eckert, Allen W. (1997) The World of Opals. (John Wiley & Sons, New York). p. 312,310. |
|
| Rocks & Min.:13:56.
USGS Bull 1538D |
|
| Christopher Wentzell collection. |
|
| (2005) Mineral Resources Data System (MRDS), US Geological Survey.
USGS Bull 1538D |
|
| Christopher Wentzell |
|
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology |
|
| USGS Bull 1538D |
|
| Rocks & Min.: 8:16
19:13.
USGS Bull 1538D |
|
| Keith Hodson, (1994) personal communication to Christopher Wentzell |
|
| USGS Bull 1538D |
|
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology |
|
| Christopher Wentzell |
- WRT Stonetree group ("Dominion Opal Mine")
| Christopher Wentzell collection. |
|
| Sinkankas, John (1959) Gemstones of North America Vol. 1. Van Nostrand Reinhold Co., New York. |
|
| Christopher Wentzell, dug 2013 October
known since 1994,C. Wentzell collection |
|
| Christopher N. Wentzell |
|
| various contributors (2013) Nevada-Jackpot! Mineral Monograph 18, Lithographie LLC, 59 |
- Mormon Mountains District
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology |
|
| Castor, Stephen B., Ferdock, Gregory C. (2004) Minerals of Nevada. Special Publication 31. Nevada Bureau of Mines and Geology |
- Central Mining District (Bayard District)
| (2005) Mineral Resources Data System (MRDS), US Geological Survey.
Northrop, Stuart A., LaBruzza, F.A. (1996) Minerals of New Mexico (3rd ed.) University of New Mexico Press, Albuquerque, NM. |
|
| Northrop, Stuart A., LaBruzza, F.A. (1996) Minerals of New Mexico (3rd ed.) University of New Mexico Press, Albuquerque, NM. |
|
| NMBMMR Bull 81 Summary of the Mineral Resources of Bernalillo, Sandoval, and Santa Fe Counties, New Mexico |
|
| Dake, H. C. (1956) Northwest Gem Trails - A Field Guide for the Gem Hunter, Mineral Collector and Tourist (2nd ed.) Gembooks. |
|
| Extra Lapis - English No. 10 Opal |
|
| www.omsinc.org (2008) http://www.omsinc.org/archives/Ore-cutts_Jan04.pdf |
|
| Dake, H. C. (1956) Northwest Gem Trails - A Field Guide for the Gem Hunter, Mineral Collector and Tourist (2nd ed.) Gembooks. |
Virgin Valley, Humboldt County, Nevada, USA